The Media/Reagents Subcore evolved from the previous Tissue Culture Media Production Core and the DNA/Molecular Biology Core. The major objective of this subcore is to provide high quality tissue culture media to diabetes investigators. It also distributes other commonly used reagents and supplies such as frozen transformation competent bacteria, bacterial culture dishes, RNA/DNA modification enzymes, and commonly used molecular biology kits at discounted prices. This subcore operates efficiently and at near maximum capacity with its current staffing. It serves more investigators now than in 1989. In 1994 there were 40 users of the media production service whereas in 1989 there were 14. This subcore met with high user approval in a presubmission review of our service facilities. Growth in the number of investigators who use this subcore is expected.